After the direct current flows through the coil,the induced magnetic field will be generated in the separating zone, and the high gradient magnetic field will be generated on the surface of matrix; By the power of slurry pump equipped with frequency control motor, the slurry will pass through the bottom of the feeding pipe to the lower yoke, and then down into the matrix area in the separating zone;Its magnetic particles will be adsorbed in the surface. Its non-magnetic particles will directly cross over the matrix, and then go through the gap of the upper yoke to drain off from the exit of the concentrate; After a period of separating time, in the condition of the magnetic particles fully absorbed, the slurry leftover in the cavity back-flow to the tank of original minerals by approaching to shut up the feeding valve and then open the reused material valve; Finishing the step of back-flowing, the reused material valve is shut up and then the tailing valve is opened up. The magnetic minerals which absorbed in the surface of the matrix will be completely washed off by the joint usage of the high pressure water flushing device and the high pressure air cleaning device;After finishing the cleaning process, the tailing valve and the reused material valve will be shut up and the feed valve reopen to feed . The new run will be started up.